(a) Minimum instrumentation, alarms, and safety controls required for specific types of automated vital systems are listed in table 1 to § 62.35-50.

(b) Automatic propulsion systems, automated electric power management systems, and all associated subsystems and equipment must be capable of meeting load demands from standby to full system rated load, under steady state and maneuvering conditions, without need for manual adjustment or manipulation.

(a) Manual propulsion control. All vessels having remote propulsion control from the navigating bridge, an ECC or maneuvering platform, or elsewhere must have a manual alternate propulsion control located at the equipment.

(b) Centralized propulsion control equipment. Navigating bridge, ECC, maneuvering platform, and manual alternate control locations must include—

(1) Control of the speed and direction of thrust for each independent propeller controlled;

(2) A guarded manually actuated safety trip control (which stops the propelling machinery) for each independent propeller controlled;

(3) Shaft speed and thrust direction indicators for each independent propeller controlled;

(4) The means to pass propulsion orders required by §§ 113.30-5 and 113.35-3 of this chapter; and

(5) The means required by paragraph (d) of this section to achieve control location transfer and independence.

(c) Main navigating bridge propulsion control. (1) Navigating bridge remote propulsion control must be performed by a single control device for each independent propeller. Control must include automatic performance of all associated services, and must not permit rate of movement of the control device to overload the propulsion machinery.

(2) On vessels propelled by steam turbines, the navigation bridge primary control system must include safety alarms for high and low boiler water levels and low steam pressure.

(3) On vessels propelled by internal combustion engines, an alarm must annunciate on the navigating bridge and at the maneuvering platform or ECC, if provided, to indicate starting capability less than 50% of that required by § 62.35-35.

(d) Transfer of control location. Transfer of control location must meet section 4-9-2/13.11 of the ABS Marine Vessel Rules (incorporated by reference; see § 62.05-1). Manual alternative-propulsion-control locations must be capable of overriding, and of operating independent of, all remote and automatic propulsion-control locations.

(e) Control system details. (1) Each operator control device must have a detent at the zero-thrust position.

(2) Propulsion machinery automatic safety trip control operation must only occur when continued operation could result in serious damage, complete breakdown, or explosion of the equipment. Other than the overrides mentioned in § 62.25-10(a)(4) and temporary overrides located at the main navigating bridge control location, overrides of these safety trip controls are prohibited. Operation of permitted overrides must be alarmed at the navigating bridge and at the maneuvering platform or ECC, as applicable, and must be guarded against inadvertent operation.

(3) Remote propulsion control systems must be failsafe by maintaining the preset (as is) speed and direction of thrust until local manual or alternate manual control is in operation, or the manual safety trip control operates. Failure must activate alarms on the navigating bridge and in the machinery spaces.

(a) Automatic bilge pumps must—

(1) Be provided with bilge high level alarms that annunciate in the machinery spaces and at a manned control location and are independent of the pump controls;

(2) Be monitored to detect excessive operation in a specified time period; and

(3) Meet all applicable pollution control requirements.

(b) Remote controls for flooding safety equipment must remain functional under flooding conditions.

(c) Remote bilge level sensors, where provided, must be located to detect flooding at an early stage and to provide redundant coverage.

(a) All required fire pump remote control locations must include the controls necessary to charge the firemain and—

(1) A firemain pressure indicator; or

(2) A firemain low-pressure alarm.

(b) [Reserved]

(a) General. (1) All main boilers, regardless of intended mode of operation, must be provided with the automatic safety trip control system(s) of paragraphs (h)(1), (h)(2)(i) and (ii), and (i) of this section to prevent unsafe conditions after light off.

(2) Manual alternate control of boilers must be located at the boiler front.

(3) A fully automatic main boiler must include—

(i) Automatic combustion control;

(ii) Programming control;

(iii) Automatic feedwater control;

(iv) Safety controls; and

(v) An alarm system.

(4) Following system line-up and starting of auxiliaries, fully automatic main boilers must only require the operator to initiate the following sequences:

(i) Boiler pre-purge.

(ii) Trial for ignition of burners subsequent to successful initial burner light-off.

(iii) Normal shutdown.

(iv) Manual safety trip control operation.

(v) Adjustment of primary control setpoints.

(5) All requirements for programming control subsystems and safety control systems must be met when a boiler—

(i) Automatically sequences burners;

(ii) Is operated from a location remote from the boiler front; or

(iii) Is fully automatic.

(6) Where light oil pilots are used, the programming control and burner safety trip controls must be provided for the light oil system. Trial for ignition must not exceed 15 seconds and the main burner trial for ignition must not proceed until the pilot flame is proven.

(b) Feedwater control. Automatic feedwater control subsystems must sense, at a minimum, boiler water level and steam flow.

(c) Combustion control. Automatic combustion control subsystems must provide—

(1) An air/fuel ratio which ensures complete combustion and stable flame with the fuel in use, under light off, steady state, and transient conditions; and

(2) Stable boiler steam pressure and outlet temperatures under steady state and transient load conditions; and

(3) A low fire interlock to prevent high firing rates and superheater damage during boiler warm up.

(d) Programming control. The programming control must provide a programed sequence of interlocks for the safe ignition and normal shutdown of the boiler burners. The programming control must prevent ignition if unsafe conditions exist and must include the following minimum sequence of events and interlocks:

(1) Prepurge. Boilers must undergo a continuous purge of the combustion chamber and convecting spaces to make sure of a minimum of 5 changes of air. The purge must not be less than 15 seconds in duration, and must occur immediately prior to the trial for ignition of the initial burner of a boiler. All registers and dampers must be open and an air flow of at least 25 percent of the full load volumetric air flow must be proven before the purge period commences. The prepurge must be complete before trial for ignition of the initial burner.

(2) Trial for ignition and ignition. (i) Only one burner per boiler is to be in trial for ignition at any time.

(ii) Total boiler air flow during light off must be sufficient to prevent pocketing and explosive accumulations of combustible gases.

(iii) The burner igniter must be in position and proven energized before admission of fuel to the boiler. The igniter must remain energized until the burner flame is established and stable, or until the trial for ignition period ends.

(iv) The trial for ignition period must be as short as practical for the specific installation, but must not exceed 15 seconds.

(v) Failure of the burner to ignite during a trial for ignition must automatically actuate the burner safety trip controls.

(3) Post-purge. (i) Immediately after normal shutdown of the boiler, an automatic purge of the boiler equal to the volume and duration of the prepurge must occur.

(ii) Following boiler safety trip control operation, the air flow to the boiler must not automatically increase. Post purge in such cases must be under manual control.

(e) Burner fuel oil valves. Each burner must be provided with a valve that is—

(1) Automatically closed by the burner or boiler safety trip control system; and

(2) Operated by the programming control or combustion control subsystems, as applicable.

(f) Master fuel oil valves. Each boiler must be provided with a master fuel oil valve to stop fuel to the boiler automatically upon actuation by the boiler safety trip control system.

(g) Valve closure time. The valves described in paragraphs (e) and (f) of this section must close within 4 seconds of automatic detection of unsafe trip conditions.

(h) Burner safety trip control system. (1) Each burner must be provided with at least one flame detector.

(2) The burner valve must automatically close when—

(i) Loss of burner flame occurs;

(ii) Actuated by the boiler safety trip control system;

(iii) The burner is not properly seated or in place; or

(iv) Trial for ignition fails, if a programming control is provided.

(i) Boiler safety trip control system. (1) Each boiler must be provided with a safety trip control system that automatically closes the master and all burner fuel oil valves upon—

(i) Boiler low-low water level;

(ii) Inadequate boiler air flow to support complete combustion;

(iii) Loss of boiler control power;

(iv) Manual safety trip operation; or

(v) Loss of flame at all burners.

(2) The low-low water level safety trip control must account for normal vessel motions and operating transients.

The starting systems for propulsion engines and for prime movers of ships' service generators required to start automatically must meet sections 4-6-5/9.5 and 4-8-2/11.11 of the ABS Marine Vessel Rules (incorporated by reference; see § 62.05-1).

(a) Level alarms. Where high or low fuel tank level alarms are required, they must be located to allow the operator adequate time to prevent an unsafe condition.

(b) Coal fuels. (1) Controls and instrumentation for coal systems require special consideration by the Commandant.

(2) Interlocks must be provided to ensure a safe transfer of machinery operation from one fuel to another.

(c) Automatic fuel heating. Automatic fuel heating must meet section 4-9-3/15.1 of the ABS Marine Vessel Rules (incorporated by reference; see § 62.05-1).

(d) Overflow prevention. Fuel oil day tanks, settlers, and similar fuel oil service tanks that are filled automatically or by remote control must be provided with a high-level alarm that annunciates in the machinery spaces and either an automatic safety trip control or an overflow arrangement.

The minimum instrumentation, alarms, and safety controls required for specific types of systems are listed in table 1 to § 62.35-50. The ABS Marine Vessel Rules (incorporated by reference; see § 62.05-2) required for engineering systems are also listed in table 1 to § 62.35-50.

(a) Safety limit controls must be provided in navigating bridge primary propulsion control systems. See § 62.35-5(c).

(b) Safety trip controls and alarms must be provided for all main boilers, regardless of mode of operation. See § 62.35-20(a).

(c) Loss of forced lubrication safety trip controls must be provided for main propulsion turbines and main propulsion diesel engines.

(d) Override of overspeed and loss of forced lubrication pressure safety trip controls must not be provided for main propulsion or generator steam or gas turbines, or diesel engines. See § 62.35-5(e)(2).

(e) Transfer interlocks must be provided for main propulsion systems capable of remote and local control.

(f) Semiconductor controlled rectifiers must have current limit controls.

(g) Interlocks must be provided to prevent the starting of engines or turbines while the jacking or turning gear, if installed, is engaged. See § 62.25-5(a).

(h) Main and remote-control stations, including the navigational bridge, must provide visual and audible alarms in the event of a fire in the main machinery space.

(i) Minimally attended and periodically unattended machinery plants must be provided with a personnel alarm that annunciates on the bridge if not acknowledged by the watch engineer. See § 62.50-20(b)(1).

(j) All automatic controls and alarms must be failsafe to the least critical consequence for the particular system. See § 62.30-1.

(k) The operating or tripped status of vital auxiliary boilers must be indicated at the ECC. See part 63 of this subchapter.